In this talk audience will be able to hear about how the long awaited Apache Solr 4.0 (aka SolrCloud) compares to the second search engine built on top of Apache Lucene – ElasticSearch. From understanding the architectural differences and behavior in situations like split – brain, to cluster recovery. From distributed indexing and document distribution control, to handling multiple shards and replicas in a single cluster. During the talk, we will also compare the most used and anticipated features such as faceting handling, documents grouping and so on. At the end we will talk about performance differences, cluster monitoring and troubleshooting.